The invention concerns more particularly an alternator of the type described and depicted in the document FR-A-2.807.889, which comprises means tending to eliminate static electricity.
This document proposes in particular a motor vehicle alternator of the type comprising:                a casing carrying a stator;        a rotor whose central shaft is mounted for rotation in the stator and consists of a so-called magnetic part comprising in particular at least the rotor shaft and pole pieces, and at least one induction winding;        and means aimed at eliminating the electrostatic charges on the alternator, by providing a permanent resistive electrical connection between the magnetic part of the rotor and its winding.        
Still for promoting the discharge of electrostatic charges, it was proposed in the French Patent Application No 03.06553 of 30 May 2003 to provide a permanent electrical connection between the rotor shaft and the case which carries the stator, with its lateral plates, and therefore with the electrical earth of the vehicle. This is because the stator proper and its casing which carries it are connected to the electrical earth of the vehicle. As described in the document EP240644, a stator can be mounted in the casing by means of a damping element such as rubber. In this case, the electrical potentials of the casing and stator may be different, the potential of the casing being however connected to the vehicle earth.
To this end, a metallic pulley which is fixed to the shaft with which it is in permanent electrical connection through its internal bore is electrically connected permanently to the lateral plate.
This connection is provided by a conductive wiper carried by the rear plate and which rubs permanently on a facing portion of the front lateral face of the pulley and/or the belt.
By way of variant of this design, as the wiper is a part liable to wear, it may belong to the belt itself and rub on the external lateral face of the rear plate.
These designs also make it possible to discharge the electrical charges which form on the belt because of the high-speed rubbing of the belt on the various pulleys which it runs over and the charges that it collects on this occasion.
The invention aims to propose means that are simple to implement for providing this electrical connection without suffering the various drawbacks related to permanent rubbing.